On June 8, 2001, at 1620 eastern daylight time, a Torno Micro Mong, N426RT, piloted by a private pilot, sustained substantial damage during an in-flight collision with the terrain, following a loss of engine power during initial climb from runway 27 (2,300 feet by 100 feet, dry/grass) at the Air Rahe Ultralight Park, Petersburg, Michigan. Visual meteorological conditions prevailed at the time of the accident. The personal flight was operating under the provisions of 14 CFR Part 91 and was not on a flight plan. The pilot, the sole occupant, sustained serious injuries. The local flight was departing at the time of the accident. According to witnesses, the aircraft departed on a westerly heading and experienced a loss of engine power approximately 70-feet above ground level (agl). The witnesses reported that after the loss of engine power, the aircraft entered a left banking turn, subsequently striking the terrain. According to the pilot's written statement, "I am unable to recall the details of the accident that occurred on June 8, 2001." Subsequent to the accident, the pilot received medical attention including major surgery and care for a resulting coma. Post-accident inspection of the aircraft engine revealed that the number-one (front) cylinder spark plug had aluminum deposits on its electrode and insulator. Further inspection of the number-one cylinder assembly revealed a hole burned in the top of its piston.